Ferrari will evaluate an F-duct on its car in practice for the Chinese Grand Prix tomorrow, as teams clamber to close down the straightline advantage enjoyed by McLaren.

BMW Sauber is the only outfit that has so far been able to successfully copy the McLaren concept, which provides a straightline speed boost through the driver closing off a valve in the cockpit that helps stall the rear wing.

Although teams all set about working on their versions of the F-duct, the fact that the McLaren has been so quick in speed traps so far this year has brought some added urgency to teams getting it onto their machines.

Sources close to Ferrari have revealed that the team is making preparations to evaluate a duct on Fernando Alonso's car during Friday's free practice session in Shanghai.

It is not clear yet how the Ferrari system is incorporated onto the F10, or if the concept is at an advanced enough stage to be raced in the Chinese Grand Prix.

Ferrari's decision comes after Felipe Massa admitted in the build-up to this weekend's race that he was concerned about the advantage McLaren was enjoying from the F-duct.

"It's a nice circuit to drive and the extremely long straight leading into a tight corner means there is a real possibility to overtake," said Massa.

"However, we will need to be careful on that straight this year, because we have seen that the McLaren in particular has a very high top speed, so in case of a close battle with them we will have to be careful and ready to defend position."

Team-mate Fernando Alonso said on Thursday that he would welcome the device.

"It will be an advantage, no doubt," Alonso said. "It is one of the longest straights in the championship and we know how efficient the McLaren is on the straights and what their top speed in the first races was.

"We saw McLaren very competitive in Malaysia, especially with Lewis [Hamilton] in the dry. But I still think that Red Bull will have a little advantage over everybody again here."

The Spaniard claimed, however, that the F-duct was not a top priority for his team.

"I know that we keep developing the car, but it's not maybe the first priority for us, that system. We keep working on our philosophies. There is an important step here to improve the car, and I know that there is more coming in the next races. I'm not specifically worried only about that system."

Other teams are also close to giving the green light to introducing the system - with Williams also possibly looking at evaluating a 'blown rear wing' in Shanghai this weekend.